The K812 wouldn't win the 'King of mid-fi' let alone the 'king of dynamics'. It has less resolution than a HD600 and high mid-range distortion combined with a zingy treble which makes it sound 'hard' with massed vocals or complex instrumental music with a lot of treble presence.
Haha! I wouldn't be so harsh. I have both and I'm happy with both. Both are stunning in their own right. At the end of the day, it depends on what sig you want at that point in time.